The present invention relates generally to vehicle seats and, more particularly, to a locking mechanism for vehicle seats which have the seatbelt secured thereto, such that additional restraints may be necessary to withstand the forces exerted by the seatbelt during sudden decelerations of the vehicle.
Vehicular seats, such as a driver seat and passenger seat, are typically mounted to a track assembly which allows for forward and rearward adjustment of the seat relative to the floor of the vehicle. Typically, a lower portion of the track assembly is anchored to the floor while an upper portion moves along the lower portion and supports a seat pan support for the seat cushion and/or seat back. Because the seat tracks may not be capable of withstanding the excessive loading of a safety belt system, which can exert extremely high forces during a sudden deceleration or collision, the safety belts in many vehicles are secured to the floor pan of the vehicle. While this provides a secure anchor for the safety belt system, the passenger or driver may have to re-adjust the seat belt after adjusting the seat position.
Many vehicle manufacturers today want the safety belts to be anchored directly to the seats, to improve the overall comfort of the passengers within the vehicle. However, the seats and the associated track assemblies must then be designed to withstand a much greater force from the seat belt during a collision, in order to prevent the seat from being dislodged from its base or pedestal. Several seat belt anchoring systems have been proposed which provide additional restraints to prevent vertical movement of the seat during collision. However, some of these restraints provide resistance to vertical movement of the seat relative to the base, but do not limit forward movement of the seat. Additionally, many of these devices include multiple moving components and/or spring mechanisms, and thus may not be easily implemented along the seat track assembly.
The present invention is intended to provide a seat interlock mechanism for a seat of a vehicle which does not interfere or restrain movement of the seat in a forwardly and/or rearwardly direction during normal operation of the seat. However, during a sudden deceleration of the vehicle, such as during a collision, the interlock mechanism may function to engage a pair of corresponding channels to restrict movement of the seat relative to the vehicle. The present invention provides an interlock bracket at an upper track portion of the seat which is movable to engage a corresponding channel at a lower track portion in response to a seat belt force exerted at the bracket which is sufficient to deform a mounting member for the interlock bracket.
According to a first aspect of the present invention, a seat interlock mechanism for retaining a seat of a vehicle to a seat base during a sudden deceleration of the vehicle comprises a deformable mounting member, a first channel member, an interlock bracket, and a seat belt mount positioned at the mounting member and/or the interlock bracket. The seat is adjustable forwardly and rearwardly along a track assembly and the interlock mechanism is positionable along at least one side of the seat. The mounting member extends laterally outwardly from at least one side of the track assembly of the seat. The first channel member is positionable at the seat base and at least partially along the track assembly. The interlock bracket is positionable at an upper track of the track assembly and includes a second channel member extending downwardly therefrom. The second channel member is positioned along the first channel member and at least initially spaced therefrom. The interlock bracket is movable to engage the second channel member with the first channel member in response to a seat belt force at the seat belt mount which is sufficient to deform the mounting member.
Preferably, the first and second channels of the interlock mechanism include corresponding teeth or notches, such that the channels non-slidably engage one another in response to the sufficient seat belt force.
In one form, the deformable mounting member is a torsion tube extending laterally across the seat and mounted at each end to an upper portion of the track assembly. The interlock bracket then rotatably receives the torsion tube therethrough, such that rotational movement of the torsion tube does not cause any corresponding movement of the interlock bracket. Preferably, the seat is a powered adjusting seat and the interlock bracket further includes an arm extending forwardly therefrom to engage and compress a portion of the adjustment mechanism at the track assembly in response to deformation of the mounting member. The compression of the adjustment mechanism retains the adjustment mechanism in full engagement with the track assembly of the seat and further limits or precludes forward motion of the seat relative to the floor of the vehicle.
According to another aspect of the present invention, a seat for a vehicle having a floor comprises a seat base securable to the floor of the vehicle, a track assembly, a seat support, a mounting member extending laterally and at least partially across the seat, a seat interlock mechanism, and a seat belt mount. The track assembly comprises an upper track and a lower track, with the lower track being secured along the seat base. The seat support is mounted to the upper track. At least one end of the mounting member extends laterally outwardly from the upper track. The seat interlock mechanism comprises a first channel positioned along the lower track and an interlock bracket mounted at the upper track and/or the laterally extending end of the mounting member. The interlock bracket includes a second channel which is aligned with and at least initially spaced from the first channel. The seat belt mount is positioned at the interlock bracket and/or the laterally extending end of the mounting member. The interlock bracket is operable to engage the second channel with the first channel in response to a seat belt force at said seat belt mount which is sufficient to deform at least one of the mounting member and the interlock bracket.
Preferably, the interlock bracket comprises a first panel and a second panel connected at least partially along an upper edge thereof. The first panel is secured to the upper track and the second panel is positioned laterally outwardly from the first panel. The mounting member extends through both first and second panels. Preferably, the mounting member is a rotatable torsion tube extending laterally across the seat for raising and lowering the seat via a powered seat mechanism. The torsion tube is rotatably received by the first and second panels of the interlock bracket.
In one form, the second or outer panel may receive the mounting member through a slotted opening to provide a time delay between an initial deformation of the mounting member and engagement of the first and second channels of the interlock mechanism. The desired time delay may be achieved through adjustment of the size of the slotted opening. Additionally, a time delay may be adjusted by varying the diameter and/or thickness of the walls of the mounting member and/or by varying the materials of the mounting member.
According to another aspect of the present invention, an interlock mechanism substantially limits forward movement of a power seat adjuster of a vehicle in response to a seat belt force exerted at the seat. The power seat adjuster is mounted at a track assembly and has a drive mechanism which is operable to rotatably actuate at least one gear member at a rack extending along the track assembly for adjusting the seat forwardly and rearwardly along the track assembly. The interlock mechanism comprises an interlock bracket which is mounted at the track assembly. The seat belt is anchored at the interlock bracket, which includes an engaging portion extending therefrom. The engaging portion is at least initially positioned adjacent to the gear member at the track assembly. The engaging portion is operable to engage and compress the gear member to retain engagement of the gear member to the rack to substantially limit forward movement of the seat in response to a seat belt force sufficient to move the interlock bracket and thus engage the engaging portion with the gear member. Compression of the gear member to the rack locks the track assembly and substantially limits or precludes slippage of the gear along the rack, which would otherwise allow forward movement of the seat during a sudden deceleration of the vehicle.
Accordingly, the present invention provides a seat interlock mechanism which functions to substantially preclude forward movement of the seat during a sudden deceleration of the vehicle via deformation or distortion of a mounting member for the interlock mechanism. The mounting member may be a torsion tube extending laterally across the seats, such that the present invention may easily be adapted for implementation on an existing design of a seat. Alternately, the mounting member may be a laterally extending member which is secured to an upper portion of the track assembly and extends laterally outwardly therefrom. The interlock mechanism is operable to substantially preclude forward movement of the seat in response to an excessive force exerted by the seat belt at the seat belt anchor, while allowing unrestricted movement of the track assembly of the seat during normal operation prior to deformation of the mounting member.
These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.